Hi Alexander,
Tiles are not the same as a typical API. The API "Get Imagery Metadata" changes the endpoint to keep pointing to the latest stitched data present. The control handles this for you so there is no need for an update mechanism like you are asking about.
I recommend taking a look at https://learn.microsoft.com/en-us/bingmaps/rest-services/directly-accessing-the-bing-maps-tiles and the two pages linked near the bottom of the article to get a better idea of how both regular map tiles and imagery tiles are structured.
Sincerely,
IoTGirl